Prognostic value of modified KDIGO staging for acute kidney injury in neonates: a prospective observational study in a level IIIB NICU

Acute kidney injury (AKI) is an increasingly recognized complication in neonates admitted to intensive care, contributing significantly to short-term morbidity and mortality. Early diagnosis and risk stratification using standardized criteria such as modified neonatal Kidney Disease Improving Global Outcomes (KDIGO) remain critical, particularly in resource-constrained tertiary units. Limited Indian studies have evaluated AKI across both term and preterm neonates in Level IIIB Neonatal Intensive Care Unit (NICU) with post-discharge growth follow-up. This prospective observational study was conducted over one year (2023–2024) in a Level IIIB NICU. Renal-function tests were performed in 645 of 925 admissions (69.7%), and all neonates fulfilling modified neonatal KDIGO criteria were included. Demographic, clinical, biochemical, and therapeutic variables were analyzed; follow-up anthropometry was assessed six weeks after discharge. Multivariate regression identified independent predictors of AKI severity and mortality. Among 925 admissions, 53 neonates met inclusion criteria for AKI, giving an incidence of 8.2%. Term neonates (56.6%) were more frequently affected than preterm. Stage 3 AKI carried the highest mortality (90%, p = 0.032). Sepsis (59%), shock (58%), and congenital heart disease (53%) were the major contributors. Inotropic support was required in 58.5% of cases. Nephrotoxic exposure occurred in 62%, predominantly to amikacin. Non-oliguric AKI was more common (70%). Post-discharge assessment showed that preterm small-for-gestational-age (SGA) infants achieved the greatest catch-up growth (38.5 g/day weight gain, 5 cm/month length velocity). The newly developed AKI risk score demonstrated an AUC of 0.81 (95% CI 0.74–0.88) for predicting severe AKI. The incidence of AKI in this Level IIIB NICU was 8.2%, with sepsis, shock, and congenital heart disease as predominant causes. The modified KDIGO criteria enabled early detection and accurate staging. Follow-up growth trends and quantified nephrotoxic exposure provide perspectives seldom addressed in prior Indian studies. Regular renal monitoring and risk-adjusted supportive care, coupled with longitudinal follow-up, are essential to improve neonatal outcomes. Clinical Trials Registry India, CTRI202306054119, 19/06/2023. Retrospectively registered.